rt-thread/components/drivers/serial/utest/v2/uart_overflow_rxb_txb.c

/*
 * Copyright (c) 2006-2025 RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2025-11-13     CYFS         Add standardized utest documentation block
*/

/**
 * Test Case Name: UART RX Buffer Overflow Handling Test
 *
 * Test Objectives:
 * - Validate UART behavior when RX FIFO exceeds configured buffer size under blocking operation
 * - Verify APIs: rt_device_find, rt_device_control(RT_DEVICE_CTRL_CONFIG / RT_SERIAL_CTRL_SET_RX_TIMEOUT),
 *   rt_device_open with RT_DEVICE_FLAG_RX_BLOCKING | RT_DEVICE_FLAG_TX_BLOCKING,
 *   rt_device_read, rt_device_write, rt_thread_create/startup
 *
 * Test Scenarios:
 * - **Scenario 1 (Overflow Stress / tc_uart_api):**
 *   1. Configure UART buffers and spawn sender thread to push large monotonic sequences while receiver drains in buffer-sized chunks.
 *   2. Delay receiver startup to force RX queue saturation, then verify data either restarts from zero (drop strategy) or continues modulo 256.
 *   3. Iterate across deterministic and random payload lengths, monitoring flags for misordered data.
 *
 * Verification Metrics:
 * - Receiver reads exactly `RT_SERIAL_TC_RXBUF_SIZE` bytes per chunk.
 * - Data pattern matches expected strategy (`RT_SERIAL_BUF_STRATEGY_DROP` or wraparound).
 * - `uart_result` remains `RT_TRUE`; `uart_over_flag` set before loop exit.
 *
 * Dependencies:
 * - Requires `RT_UTEST_SERIAL_V2` with loopback wiring and optional DMA ping buffer support.
 * - UART driver must implement overflow strategy macros and blocking modes.
 * - Adequate heap for large TX/RX buffers and 2 KB thread stacks.
 *
 * Expected Results:
 * - No assertions triggered; logs report pass counts for each length.
 * - Utest harness prints `[  PASSED  ] [ result   ] testcase (components.drivers.serial.v2.uart_overflow_rxb_txb)`.
 */

#include <rtthread.h>
#include "utest.h"
#include <rtdevice.h>
#include <stdlib.h>


#ifdef RT_UTEST_SERIAL_V2

static struct rt_serial_device *serial;
static rt_uint8_t               uart_over_flag = RT_FALSE;
static rt_bool_t                uart_result    = RT_TRUE;

static rt_err_t uart_find(void)
{
    serial = (struct rt_serial_device *)rt_device_find(RT_SERIAL_TC_DEVICE_NAME);

    if (serial == RT_NULL)
    {
        LOG_E("find %s device failed!\n", RT_SERIAL_TC_DEVICE_NAME);
        return -RT_ERROR;
    }

    return RT_EOK;
}


static void uart_send_entry(void *parameter)
{
    rt_uint32_t send_len;
    rt_uint8_t *uart_write_buffer = RT_NULL;
    rt_uint32_t i                 = 0;
    send_len                      = *(rt_uint32_t *)parameter;

    /* assign send buffer */
    uart_write_buffer = (rt_uint8_t *)rt_malloc(send_len);
    if (uart_write_buffer == RT_NULL)
    {
        LOG_E("Without spare memory for uart dma!");
        uart_result = RT_FALSE;
        return;
    }

    rt_memset(uart_write_buffer, 0, send_len);

    for (i = 0; i < send_len; i++)
    {
        uart_write_buffer[i] = (rt_uint8_t)i;
    }
    /* send buffer */
    if (rt_device_write(&serial->parent, 0, uart_write_buffer, send_len) != send_len)
    {
        LOG_E("device write failed\r\n");
    }
    rt_free(uart_write_buffer);
}

static void uart_rec_entry(void *parameter)
{
    rt_uint32_t rev_len;
    rt_uint8_t *uart_write_buffer;
    rt_int32_t  cnt, i;
    rev_len           = *(rt_uint32_t *)parameter;
    uart_write_buffer = (rt_uint8_t *)rt_malloc(rev_len + 1);

    while (1)
    {
        cnt = rt_device_read(&serial->parent, 0, (void *)uart_write_buffer, RT_SERIAL_TC_RXBUF_SIZE);
        if (cnt != RT_SERIAL_TC_RXBUF_SIZE)
        {
            uart_result = RT_FALSE;
            rt_free(uart_write_buffer);
            return;
        }

#ifdef RT_SERIAL_BUF_STRATEGY_DROP
        for (i = 0; i < cnt; i++)
        {
            if (uart_write_buffer[i] != i)
            {
                LOG_E("Read Different data2 -> former data: %x, current data: %x.", uart_write_buffer[i], i);
                uart_result = RT_FALSE;
                rt_free(uart_write_buffer);
                return;
            }
        }
#else
        for (i = cnt - 1; i >= 0; i--)
        {
            if (uart_write_buffer[i] != ((rev_len - (cnt - i)) % (UINT8_MAX + 1)))
            {
                LOG_E("Read Different data2 -> former data: %x, current data: %x.", uart_write_buffer[i], ((rev_len - (cnt - i)) % (UINT8_MAX + 1)));
                uart_result = RT_FALSE;
                rt_free(uart_write_buffer);
                return;
            }
        }
#endif /* RT_SERIAL_BUF_STRATEGY_DROP */
        break;
    }
    rt_free(uart_write_buffer);
    uart_over_flag = RT_TRUE;
}

static rt_err_t uart_api(rt_uint32_t length)
{
    rt_thread_t thread_send = RT_NULL;
    rt_thread_t thread_recv = RT_NULL;
    rt_err_t    result      = RT_EOK;
    uart_over_flag          = RT_FALSE;

    result = uart_find();
    if (result != RT_EOK)
    {
        return -RT_ERROR;
    }

    /* Reinitialize */
    struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;
    config.baud_rate               = BAUD_RATE_115200;
    config.rx_bufsz                = RT_SERIAL_TC_RXBUF_SIZE;
    config.tx_bufsz                = RT_SERIAL_TC_TXBUF_SIZE;
#ifdef RT_SERIAL_USING_DMA
    config.dma_ping_bufsz = RT_SERIAL_TC_RXBUF_SIZE / 2;
#endif
    rt_device_control(&serial->parent, RT_DEVICE_CTRL_CONFIG, &config);

    result = rt_device_open(&serial->parent, RT_DEVICE_FLAG_RX_BLOCKING | RT_DEVICE_FLAG_TX_BLOCKING);
    if (result != RT_EOK)
    {
        LOG_E("Open uart device failed.");
        uart_result = RT_FALSE;
        return -RT_ERROR;
    }

    rt_int32_t timeout = 5000;
    rt_device_control(&serial->parent, RT_SERIAL_CTRL_SET_RX_TIMEOUT, (void *)&timeout);

    thread_send = rt_thread_create("uart_send", uart_send_entry, &length, 2048, RT_THREAD_PRIORITY_MAX - 4, 10);
    thread_recv = rt_thread_create("uart_recv", uart_rec_entry, &length, 2048, RT_THREAD_PRIORITY_MAX - 5, 10);
    if ((thread_send != RT_NULL) && (thread_recv != RT_NULL))
    {
        rt_thread_startup(thread_send);
        /* waiting for data transmission to complete*/
        rt_thread_mdelay(length * 0.0868 + 10);
        rt_thread_startup(thread_recv);
    }
    else
    {
        result = -RT_ERROR;
        goto __exit;
    }

    while (1)
    {
        if (uart_result != RT_TRUE)
        {
            LOG_E("The test for uart dma is failure.");
            result = -RT_ERROR;
            goto __exit;
        }
        if (uart_over_flag == RT_TRUE)
        {
            goto __exit;
        }
        /* waiting for test over */
        rt_thread_mdelay(5);
    }
__exit:
    rt_device_close(&serial->parent);
    rt_thread_mdelay(5);
    return result;
}

static void tc_uart_api(void)
{
    rt_uint32_t count = 0;
    rt_uint16_t num   = 0;
    rt_uint32_t i     = 0;

    for (i = 1; i < 10; i++)
    {
        if (uart_api(RT_SERIAL_TC_TXBUF_SIZE * i + i % 2) == RT_EOK)
            LOG_I("data_lens [%4d], it is correct to read and write data. [%d] count testing.", RT_SERIAL_TC_TXBUF_SIZE * i + i % 2, ++count);
        else
        {
            LOG_E("uart test error");
            goto __exit;
        }
    }

    for (i = 1; i < 10; i++)
    {
        if (uart_api(RT_SERIAL_TC_RXBUF_SIZE * i + i % 2) == RT_EOK)
            LOG_I("data_lens [%4d], it is correct to read and write data. [%d] count testing.", RT_SERIAL_TC_RXBUF_SIZE * i + i % 2, ++count);
        else
        {
            LOG_E("uart test error");
            goto __exit;
        }
    }

    srand(rt_tick_get());
    while (RT_SERIAL_TC_SEND_ITERATIONS - count)
    {
        num = (rand() % RT_SERIAL_TC_RXBUF_SIZE) + 1;
        if (uart_api(num + RT_SERIAL_TC_RXBUF_SIZE) == RT_EOK)
            LOG_I("data_lens [%3d], it is correct to read and write data. [%d] count testing.", num, ++count);
        else
        {
            LOG_E("uart test error");
            break;
        }
    }

__exit:
    uassert_true(uart_result == RT_TRUE);
}

static rt_err_t utest_tc_init(void)
{
    LOG_I("UART TEST: Please connect Tx and Rx directly for self testing.");
    return RT_EOK;
}

static rt_err_t utest_tc_cleanup(void)
{
    uart_result          = RT_TRUE;
    uart_over_flag       = RT_FALSE;
    rt_device_t uart_dev = rt_device_find(RT_SERIAL_TC_DEVICE_NAME);
    while (rt_device_close(uart_dev) != -RT_ERROR);
    return RT_EOK;
}

static void testcase(void)
{
    UTEST_UNIT_RUN(tc_uart_api);
}

UTEST_TC_EXPORT(testcase, "components.drivers.serial.v2.uart_overflow_rxb_txb", utest_tc_init, utest_tc_cleanup, 30);

#endif /* TC_UART_USING_TC */